The invention relates to a carburetor comprising a housing in which an intake passage section is formed, wherein in the intake passage section a throttle element and upstream of the throttle element a choke element are arranged. The carburetor further comprises at least one fuel opening that opens downstream of the choke element into the intake passage section and also comprises a fuel valve that controls the fuel quantity supplied to the fuel opening.
U.S. Pat. No. 6,932,058 discloses a carburetor in which the fuel quantity supplied to the intake passage is controlled by a switch valve as a function of the engine speed of the internal combustion engine. In this way, the internal combustion engine can be kept ready to run even with the starter device being engaged.
During start-up while the starting device is engaged, the internal combustion engine is supplied with only a minimal amount of combustion air. In accordance with this, the fuel quantity that is supplied to the intake passage section must also be minimal. At full load of the internal combustion engine it must be ensured that the intake passage section can be supplied with the entire required fuel quantity and, for this purpose, the fuel valve must have a sufficiently large maximum throughput. It has been found that designing the fuel valve, in particular in carburetors of internal combustion engines with comparatively large engine displacement, can be a difficult task because fuel valves that provide for a sufficiently large throughput cannot meter minimal fuel quantities in a sufficiently precise way.
It is therefore an object of the present invention to provide a carburetor of the aforementioned kind that enables a precise metering of small fuel quantities and at the same time is capable of supplying a sufficiently large maximum fuel quantity.